The present invention generally relates to a nozzle and, more particularly, to a nozzle that has an adjustable smooth bore.
Smooth bore nozzles are well known in the art and are configured with a gradually diminishing inner diameter from their input end to their discharge or output end to increase fluid flow from a fire hose on which the nozzle is mounted. One disadvantage to smooth bore nozzles is that they have a fixed diameter. As a result, they provide a limited flow rate range, with the fluid pressure driving the flow rate change. For example, a one inch diameter smooth bore nozzle will flow approximately 184 gallons per minute at approximately a 50 psi discharge pressure. However, if the fire hose discharge pressure is increased to 70 psi, the flow rate will increase to approximately 247 gallons per minute.
Heretofore, in order to change the flow rate from a fire hose, the smooth bore nozzle is either replaced with a smooth bore nozzle with a different diameter or a fitting or tip is added to or removed from the nozzle to change in the inner diameter of the nozzle. For example, when a one inch diameter smooth bore nozzle is substituted with a 1.25 inch diameter smooth bore nozzle, the flow will increase to approximately 326 gallons per minute with the same 50 psi discharge pressure. Or as noted, it has also been common practice to have smooth bore nozzles with multiple fittings or tips with each fitting or tip having a different diameter. Each fitting is threaded onto the nozzle to adjust the inner diameter of the nozzle. However, in either case this requires the user to shut off the water supply when changing the nozzle or adding or removing a fitting to change the nozzle diameter. As a result, this can create downtime for the firefighter.
Accordingly, there is a need for a smooth bore nozzle whose flow rate can be adjusted without having to shut off the water flow.